Field of the Invention
The present invention relates to a hydraulic pressure supply system for an automatic transmission of a vehicle. More particularly, the present invention relates to a hydraulic pressure supply system for an automatic transmission of a vehicle for maximizing reduction of fuel consumption and minimizing capacity of a mechanical oil pump as an auxiliary function of an electric pump.
Description of Related Art
In recent years, as higher oil prices worldwide and exhaust gas discharge regulations have become more restrictive, car makers have devoted all their power to technological development which is environmentally friendly and can improve fuel efficiency.
Fuel efficiency in an automatic transmission may be improved by improving power transmission efficiency, and the power transmission efficiency can be improved by minimizing unnecessary power consumption in the oil pump.
However, in a conventional system, hydraulic pressure pumped by the mechanical pump driven by engine power is controlled by a pressure control valve and then supplied to each transmission unit, and accordingly, the amount of oil cannot be controlled, thereby causing unnecessary power loss.
In particular, generation of unnecessary hydraulic pressure at a high RPM area causes power loss, thereby reducing fuel efficiency.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.